'\" et
.TH sys_wait.h "0P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
sys/wait.h
\(em declarations for waiting
.SH SYNOPSIS
.LP
.nf
#include <sys/wait.h>
.fi
.SH DESCRIPTION
The
.IR <sys/wait.h> 
header shall define the following symbolic constants for use with
\fIwaitpid\fR():
.IP WCONTINUED 14
Report status of continued child process.
.IP WNOHANG 14
Do not hang if no status is available; return immediately.
.IP WUNTRACED 14
Report status of stopped child process.
.P
The
.IR <sys/wait.h> 
header shall define the following macros for analysis of process status
values:
.IP WEXITSTATUS 14
Return exit status.
.IP WIFCONTINUED 14
True if child has been continued.
.IP WIFEXITED 14
True if child exited normally.
.IP WIFSIGNALED 14
True if child exited due to uncaught signal.
.IP WIFSTOPPED 14
True if child is currently stopped.
.IP WSTOPSIG 14
Return signal number that caused process to stop.
.IP WTERMSIG 14
Return signal number that caused process to terminate.
.P
The
.IR <sys/wait.h> 
header shall define the following symbolic constants as possible values
for the
.IR options
argument to
\fIwaitid\fR():
.IP WEXITED 14
Wait for processes that have exited.
.IP WNOWAIT 14
Keep the process whose status is returned in
.IR infop
in a waitable state.
.IP WSTOPPED 14
Status is returned for any child that has stopped upon receipt of a
signal.
.P
The
WCONTINUED
and WNOHANG constants, described above for
\fIwaitpid\fR(),
can also be used with
\fIwaitid\fR().
.P
The type
.BR idtype_t
shall be defined as an enumeration type whose possible values shall
include at least the following:
P_ALL
P_PGID
P_PID
.P
The
.IR <sys/wait.h> 
header shall define the
.BR id_t
and
.BR pid_t
types as described in
.IR <sys/types.h> .
.P
The
.IR <sys/wait.h> 
header shall define the
.BR siginfo_t
type and the
.BR sigval
union as described in
.IR <signal.h> .
.P
Inclusion of the
.IR <sys/wait.h> 
header may also make visible
all symbols from
.IR <signal.h> .
.P
The following shall be declared as functions and may also be defined
as macros. Function prototypes shall be provided.
.sp
.RS 4
.nf

pid_t  wait(int *);
int    waitid(idtype_t, id_t, siginfo_t *, int);
pid_t  waitpid(pid_t, int *, int);
.fi
.P
.RE
.LP
.IR "The following sections are informative."
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fB<signal.h>\fP",
.IR "\fB<sys_resource.h>\fP",
.IR "\fB<sys_types.h>\fP"
.P
The System Interfaces volume of POSIX.1\(hy2017,
.IR "\fIwait\fR\^(\|)",
.IR "\fIwaitid\fR\^(\|)"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
